U.S. patent application number 15/758290 was filed with the patent office on 2018-09-27 for rotary electric machine.
The applicant listed for this patent is EXEDY CORPORATION. Invention is credited to Kousuke MURATA.
Application Number | 20180278109 15/758290 |
Document ID | / |
Family ID | 58695047 |
Filed Date | 2018-09-27 |
United States Patent
Application |
20180278109 |
Kind Code |
A1 |
MURATA; Kousuke |
September 27, 2018 |
ROTARY ELECTRIC MACHINE
Abstract
A rotary electric machine includes a rotary shaft, a rotor
provided on the rotary shaft, a stator and a housing. The stator
includes a stator core, which is disposed on an outer periphery of
the rotor, and a coil that is wound about the stator core and
includes end coils exposed from the stator core in directions
oriented along an axial direction of the rotary shaft. The housing,
by which the rotary shaft is rotatably supported, accommodates the
rotor and the stator in the interior thereof, and is provided with
a housing flow pathway on an inner wall surface thereof. The
housing flow pathway is serial and causes a liquid coolant for
cooling an outer periphery of the stator core and the end coils to
flow therethrough.
Inventors: |
MURATA; Kousuke;
(Neyagawa-shi, Osaka, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
EXEDY CORPORATION |
Neyagawa-shi, Osaka |
|
JP |
|
|
Family ID: |
58695047 |
Appl. No.: |
15/758290 |
Filed: |
October 21, 2016 |
PCT Filed: |
October 21, 2016 |
PCT NO: |
PCT/JP2016/081302 |
371 Date: |
March 7, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H02K 9/19 20130101; H02K
3/24 20130101; H02K 5/20 20130101 |
International
Class: |
H02K 3/24 20060101
H02K003/24; H02K 5/20 20060101 H02K005/20; H02K 9/19 20060101
H02K009/19 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 13, 2015 |
JP |
2015-222735 |
Claims
1. A rotary electric machine comprising: a rotary shaft; a rotor
provided on the rotary shaft; a stator including a stator core and
a coil, the stator core disposed on an outer periphery of the
rotor, the coil being wound about the stator core, the coil
including end coils, the end coils being exposed from the stator
core in directions oriented along an axial direction of the rotary
shaft; and a housing by which the rotary shaft is rotatably
supported, the housing accommodating the rotor and the stator in an
interior thereof, the housing being provided with a housing flow
pathway on an inner wall surface thereof, the housing flow pathway
being serial, the housing flow pathway for causing a liquid coolant
for cooling an outer periphery of the stator core and the end coils
to flow therethrough.
2. The rotary electric machine according to claim 1, wherein the
housing includes an inlet for flowing the liquid coolant into the
housing flow pathway, and the liquid coolant is introduced into the
housing flow pathway through the inlet, flows along the outer
periphery of the stator core and then flows toward the end
coils.
3. The rotary electric machine according to claim 1, further
comprising: a pair of covers disposed on both end parts of the
housing in the axial direction of the rotary shaft so as to be
opposed to the end coils, the pair of covers being integrated or
separated from the housing, wherein a shaft end flow pathway is
provided between an axial end surface of the stator core and each
of the pair of covers so as to communicate with the housing flow
pathway.
4. The rotary electric machine according to claim 3, wherein the
housing includes an outlet for discharging the liquid coolant that
flows thereto from the shaft end flow pathway to a drain.
5. The rotary electric machine according to claim 3, wherein the
housing flow pathway includes an annular flow pathway provided
around an entire circumference of the inner wall surface of the
housing, and an axial flow pathway provided on the inner wall
surface of the housing, the axial flow pathway extending to outer
peripheral sides of the end coils in the directions oriented along
the axial direction of the rotary shaft, the axial flow pathway for
communicating with the annular flow pathway.
6. The rotary electric machine according to claim 5, wherein the
shaft end flow pathway communicates with the axial flow pathway.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is the U.S. National Phase of PCT
International Application No. PCT/JP2016/081302, filed on Oct. 21,
2016. That application claims priority to Japanese Patent
Application No. 2015-222735, filed Nov. 13, 2015. The contents of
both applications are herein incorporated by reference in their
entirety.
BACKGROUND
Technical Field
[0002] The present disclosure relates to a rotary electric machine,
particularly to a rotary electric machine including a flow pathway
for cooling.
Background Information
[0003] Rotary electric machines have been used as power sources for
hybrid cars, electric vehicles and so forth. The rotary electric
machines are required to be cooled due to heat released therefrom
in use. In a rotary electric machine described in Japan Laid-open
Patent Application Publication No. 2014-107905, for instance, a
rotor and a stator are disposed inside a housing, and a flow
pathway for a liquid coolant is further provided in the housing.
The flow pathway is provided in an upper part of the housing along
the axial direction of a rotary shaft, and supplies the liquid
coolant to the interior of the housing.
BRIEF SUMMARY
[0004] In the rotary electric machine of Japan Laid-open Patent
Application Publication No. 2014-107905, as described above, the
flow pathway supplied with the liquid coolant is provided in the
interior of the housing. Moreover, the liquid coolant is supplied
to the outer periphery of the stator and a coil from the flow
pathway through a plurality of ejection holes. In the configuration
herein described, the liquid coolant is supplied to the outer
periphery of the stator and the coil in a parallel manner from the
flow pathway through the plural ejection holes. Hence, it is
required to increase the total flow rate of the liquid coolant.
[0005] It is an object of the present disclosure to make it
possible to efficiently cool a stator and a coil, with the flow
rate of a liquid coolant being inhibited.
[0006] (1) A rotary electric machine according to the present
disclosure includes a rotary shaft, a rotor provided on the rotary
shaft, a stator and a housing. The stator includes a stator core,
which is disposed on an outer periphery of the rotor, and a coil
that is wound about the stator core and includes end coils exposed
from the stator core in directions oriented along an axial
direction of the rotary shaft. The housing, by which the rotary
shaft is rotatably supported, accommodates the rotor and the stator
in an interior thereof, and is provided with a housing flow pathway
on an inner wall surface thereof. The housing flow pathway is
serial and causes a liquid coolant for cooling an outer periphery
of the stator core and the end coils to flow therethrough.
[0007] The stator core and the end coils are herein cooled through
the serial housing flow pathway provided on the inner wall surface
of the housing. In other words, the liquid coolant cools the stator
core and the end coils by flowing through the housing flow pathway
in a serial manner. Hence, compared to a well-known configuration
to flow a liquid coolant in a parallel manner, the respective parts
can be efficiently cooled will less liquid coolant.
[0008] (2) Preferably, the housing includes an inlet for flowing
the liquid coolant into the housing flow pathway. Additionally, the
liquid coolant is introduced into the housing flow pathway through
the inlet, flows along the outer periphery of the stator core, and
then flows toward the end coils.
[0009] When the temperature of the stator core and that of the end
coils are herein considered, the temperature of the end coils
becomes higher than that of the stator core. Therefore, when it is
assumed that the liquid coolant is flown from each end coil side
toward the stator core, the liquid coolant flows to the stator core
after heated by each end coil. Hence, the stator core cannot be
efficiently cooled.
[0010] In view of this, the liquid coolant is herein configured to
be flown from the stator core with low temperature to each end coil
with high temperature.
[0011] (3) Preferably, the rotary electric machine further includes
a pair of covers that is disposed on both end parts of the housing
in the axial direction of the rotary shaft so as to be opposed to
the end coils and is integrated or separated from the housing.
Moreover, a shaft end flow pathway is provided between an axial end
surface of the stator core and each of the pair of covers so as to
communicate with the housing flow pathway.
[0012] The liquid coolant is herein supplied to the shaft end flow
pathway after flowing through the housing flow pathway. Then, the
liquid coolant flows through the shaft end flow pathway, whereby
the end coils can be efficiently cooled.
[0013] (4) Preferably, the housing includes an outlet for
discharging the liquid coolant flowing thereto from the shaft end
flow pathway to a drain.
[0014] (5) Preferably, the housing flow pathway includes an annular
flow pathway and an axial flow pathway. The annular flow pathway is
provided around an entire circumference of the inner wall surface
of the housing. The axial flow pathway is provided on the inner
wall surface of the housing, extends to outer peripheral sides of
the end coils in the directions oriented along the axial direction
of the rotary shaft, and communicates with the annular flow
pathway.
[0015] (6) Preferably, the shaft end flow pathway communicates with
the axial flow pathway.
[0016] In the present advancement as described above, the stator
and the coil can be efficiently cooled, with the total flow rate of
the liquid coolant being inhibited.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a vertical cross-sectional view of a rotary
electric machine according to an exemplary embodiment of the
present disclosure.
[0018] FIG. 2 is a front cross-sectional view of a housing of the
rotary electric machine.
[0019] FIG. 3 is a perspective view of the appearance of the
housing.
[0020] FIG. 4 is a front cross-sectional view of a housing
according to another exemplary embodiment.
DETAILED DESCRIPTION OF EMBODIMENTS
[0021] FIG. 1 shows a rotary electric machine 1 according to an
exemplary embodiment of the present disclosure. FIG. 1 is a
vertical cross-sectional view of the rotary electric machine 1. The
rotary electric machine 1 includes a rotary shaft 2, a rotor 3
provided on the rotary shaft 2, a stator 4, a housing 5, a first
cover 6 integrated with the housing 5, and a second cover 7
detachably attached to the housing 5.
[0022] [Device Configuration]
[0023] The rotary shaft 2 is rotatably supported at both ends
thereof by the first cover 6 and the second cover 7 through
bearings 10 and 11, and is thus supported by the housing 5.
[0024] The rotor 3 is attached to the rotary shaft 2, and includes
a rotor core 13 and a pair of end plates 14a and 14b. The rotor
core 13 is configured by laminating a plurality of magnetic plates
along the axial direction of the rotary shaft 2. The pair of end
plates 14a and 14b is attached to both axial ends of the rotor core
13, respectively.
[0025] The stator 4 includes a stator core 16 and a coil 17. The
stator core 16 is formed by laminating a plurality of magnetic
plates along the axial direction of the rotary shaft 2. The coil 17
is wound about the stator core 16, and has approximately the same
length as the rotor core 13 in the axial direction. Additionally,
the coil 17 includes end coils 17a and 17b exposed from the stator
core 16 in directions oriented along the axial direction.
[0026] The housing 5 is made in the shape of a cylinder that
includes the first cover 6 on one axial end side thereof and is
also opened on the other axial end side thereof. Additionally, the
second cover 7 is attached to the other end side. The rotor 3 and
the stator 4 are accommodated in the interior of the housing 5.
[0027] A first sleeve 21 and a second sleeve 22 are disposed on the
inner peripheral surfaces of both axial end parts of the housing 5.
The first sleeve 21 is disposed between the first cover 6 and one
end surface of the stator core 16 so as to be radially opposed to
the end coil 17a. On the other hand, the second sleeve 22 is
disposed between the second cover 7 and the other end surface of
the stator core 16 so as to be radially opposed to the end coil
17b. It should be noted that each of the first and second sleeves
21 and 22 is made of an insulating material to insulate the housing
5 and each of the end coils 17a and 17b from each other.
[0028] A seal member 24 is disposed between the first cover 6 and
one end surface of the first sleeve 21, whereas a seal member 25 is
disposed between the second cover 7 and the second sleeve 22. It
should be noted that although not provided in FIG. 1, seal members
may be disposed between one end surface of the stator core 16 and
the other end surface of the first sleeve 21 and between the other
end surface of the stator core 16 and the other end surface of the
second sleeve 22, respectively.
[0029] [Cooling Structure]
[0030] The present rotary electric machine 1 includes a cooling
structure for mainly cooling the stator core 16 and the end coils
17a and 17b with a liquid coolant. The cooling structure includes a
housing flow pathway 28, which is provided in the housing 5, and a
shaft end flow pathway 29, which is provided between the housing 5
and the first and second covers 6 and 7.
[0031] As shown in FIGS. 2 and 3, the housing flow pathway 28
includes an annular groove (annular flow pathway) 28a and an axial
groove (axial flow pathway) 28b. It should be noted that FIG. 2 is
a front cross-sectional view of the housing 5, whereas FIG. 3 is a
perspective view of the appearance of the housing 5.
[0032] The annular groove 28a is provided around the entire
circumference of the inner wall surface of the housing 5. The
annular groove 28a is shorter than the stator core 16 in the axial
direction, but has approximately the same length as the entire
length of the stator core 16. Additionally, an inlet 5a is provided
in the lower end part of the housing 5, and penetrates the housing
5 so as to communicate with the annular groove 28a.
[0033] The axial groove 28b is provided to extend in the axial
direction. The axial groove 28b communicates with the annular
groove 28a, and is provided to extend from the end part of the
first cover 6 to the second cover 7. In other words, the axial
groove 28b is provided to extend from the outer periphery of the
first sleeve 21 to that of the second sleeve 22. Additionally,
communication holes 21a and 22a are provided in the first and
second sleeves 21 and 22, respectively, while radially penetrating
therethrough so as to communicate with the axial groove 28b.
[0034] The shaft end flow pathway 29 includes a first shaft end
flow pathway 29a on the first cover 6 side and a second shaft end
flow pathway 29b on the second cover 7 side. The first shaft end
flow pathway 29a communicates with the axial groove 28b of the
housing flow pathway 28 through the communication hole 21a of the
first sleeve 21. ON the other hand, the second shaft end flow
pathway 29b communicates with the axial groove 28b of the housing
flow pathway 28 through the communication hole 22a of the second
sleeve 22.
[0035] The first shaft end flow pathway 29a is provided between the
first cover 6 and one end surface (axial end surface) of the stator
core 16. In other words, the first shaft end flow pathway 29a is
provided to flow the liquid coolant to the axial end surface and
outer peripheral part of the end coil 17a. On the other hand, the
second shaft end flow pathway 29b is provided between the second
cover 7 and the other end surface (axial end surface) of the stator
core 16. In other words, the second shaft end flow pathway 29b is
provided to flow the liquid coolant to the axial end surface and
outer peripheral part of the end coil 17b.
[0036] Holes 21b and 22b are provided in the lower end parts of the
first and second sleeves 21 and 22, respectively, while radially
penetrating therethrough. Additionally, first and second outlets 5b
and 5c are provided in the lower end part of the housing 5 so as to
communicate with these holes 21b and 22b, respectively. These first
and second outlets 5b and 5c are connected to a drain.
[0037] In the configuration described above, the outer periphery of
the stator core 16 and one end coil 17a can be cooled by flowing
the liquid coolant through a first serial flow pathway: the inlet
5a.fwdarw.the annular groove 28a.fwdarw.the axial groove
28b.fwdarw.the first shaft end flow pathway 29a.fwdarw.the first
outlet 5b. On the other hand, the outer periphery of the stator
core 16 and the other end coil 17b can be cooled by flowing the
liquid coolant through a second serial flow pathway: the inlet
5a.fwdarw.the annular groove 28a.fwdarw.the axial groove
28b.fwdarw.the second shaft end flow pathway 29b.fwdarw.the second
outlet 5c.
[0038] Here, the stator core 16 and each end coil 17a, 17b can be
cooled by flowing the liquid coolant along each serial flow
pathway. Therefore, compared to a well-known cooling configuration
by flowing a liquid coolant in a parallel manner, it is possible to
inhibit a flow rate necessary for a liquid coolant and compactly
produce a pump for the liquid coolant.
[0039] Additionally, the liquid coolant is flown to the stator core
16, the temperature of which is relatively low, and is then flown
to each end coil 17a, 17b, the temperature of which becomes higher
than the stator core 16. Hence, it is possible to efficiently cool
the stator core 16 and each end coil 17a, 17b.
OTHER EXEMPLARY EMBODIMENTS
[0040] The present advancement is not limited to the exemplary
embodiment described above, and a variety of changes or
modifications can be made without departing from the scope of the
present disclosure.
[0041] In the aforementioned exemplary embodiment, the inlet 5a for
the liquid coolant is provided in the lower end part of the housing
5. However, as shown in FIG. 4, an inlet 5'd may be provided in the
upper part of a housing 5', and a liquid coolant may be configured
to be flown in one direction along the annular groove 28a so as to
be flown to the axial groove 28b.
INDUSTRIAL APPLICABILITY
[0042] In a rotary electric machine of the present disclosure, a
stator and a coil can be efficiently cooled, with the total flow
rate of a liquid coolant being inhibited.
REFERENCE SIGNS LIST
[0043] 1 Rotary electric machine [0044] 2Rotary shaft [0045] 3
Rotor [0046] 4 Stator [0047] 5 Housing [0048] 5a Inlet [0049] 5b,
5c Outlet [0050] 6 First cover [0051] 7 Second cover [0052] 16
Stator core [0053] 17 Coil [0054] 17a, 17b End coil [0055] 28
Housing flow pathway [0056] 28a Annular groove (annular flow
pathway) [0057] 28b Axial groove (axial flow pathway) [0058] 29
Shaft end flow pathway
* * * * *